1. Field of the Invention
The present invention relates to an exhaust gas post processing method and system. More particularly, the present invention relates to an exhaust gas post processing method for trapping particulate matter included in an exhaust gas and eliminating it, and a system performing the method.
2. Description of the Related Art
Reducing harmful matter is an important problem in a diesel automobile that generates a large amount of harmful exhaust gas. Particularly, it is necessary to reduce PM (particulate matter) caused by incomplete combustion of a fuel.
A variety of techniques have been introduced to reduce the PM, and among them there is a DPF (diesel particulate filter) for trapping the PM of the exhaust gas and raising the temperature of the trapped PM to a temperature higher than the ignition point thereof to be eliminated.
Soot particles like carbon are trapped in the diesel particulate filter, the trapped PM is combusted, but the unburned remainder is not eliminated but is deposited within the DPF.
The deposited matter that is not burned is called “ash”, and it becomes important to precisely estimate the ash amount and to detect the PM amount based on the ash amount.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.